It is known that the flight control computers perform, inter alia, the position feedback control of the control surfaces of an aircraft, for example a transport aeroplane. The movement of the control surface is generated by an actuator which may be either in active mode or in passive mode. In general, two actuators are provided per control surface. A so-called “master” computer produces the feedback control, by sending a control command via the active actuator. The other actuator, associated with a second, so-called “slave” computer, is forced in passive mode to follow the movement of the control surface. If, via specific monitoring means, the master computer detects a malfunction, it switches the active actuator into passive mode, and gives the control to the slave computer which controls the second actuator (then switched into active mode).
The jamming and/or uncontrolled movement of a control surface, as a function of the flight point of the aircraft, may have consequences for the guidance of said aircraft, on the dimensioning of its structure by virtue of the loads generated and also on its performance. It is therefore necessary to be able to detect such a malfunction sufficiently quickly before the consequences for the aircraft are too great, in particular in order to be able to alert the flight crew so that they can perform the actions limiting the consequences of this malfunction or in order to proceed with an automatic reconfiguration of the system.